The purpose of this study was to measure noise levels during aerobics classes and to examine how outer hair cell (OHC) function, using distortion product otoacoustic emissions (DPOAEs), may be affected by this exposure. Fifty individuals (48 women and 2 men, ages 19-41 years) participated in 50-min aerobics classes. Noise levels were measured using noise dosimeters placed on the collar near the test ear. The audiometric protocol consisted of a questionnaire, otoscopy, screening tympanometry, and pre- and post-aerobics DPOAEs. The minute-by-minute peak noise levels varied between 90.5 and 99.7 dBA. The overall mean noise level for the aerobics classes was 87.1 dBA (range=83.4-90.7 dBA). Mean post-aerobic DPOAE levels were lower at most frequencies with a statistically significant 1.4 dB decrease at 6000 Hz. Results of this project, even with limited statistical significance, should be viewed cautiously. Learning outcomes: The reader will be able to (1) identify the approximate dB SPL measured during aerobics classes, (2) describe what effects, if any, these levels had on DPOAEs, and (3) discuss what specific frequency had a significant decrease in DPOAE level after an aerobics class. (Contains 1 table and 2 figures.)